Adapter for securing loading units to handle assemblies of surgical stapling instruments

ABSTRACT

An adapter for releasably connecting a loading unit to a handle assembly includes a proximal drive shaft, a distal drive shaft, and a shear pin connecting the proximal drive shaft to the distal drive shaft. The proximal drive shaft includes proximal and distal portions. The proximal portion of the proximal drive shaft is configured for releasable connection to the handle assembly. The distal drive shaft includes proximal and distal portions. The distal portion of the distal drive shaft being configured for releasable connection to the loading unit. The shear pin is configured to rotationally fix the proximal drive shaft to the distal drive shaft and is configured to fracture to permit rotation of the proximal drive shaft independent of rotation of the distal drive shaft when a predetermined torque is applied to the distal drive shaft.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of and prior to U.S. Provisional Patent Application No. 63/084,750, filed on Sep. 29, 2020, the content of which is incorporated herein by reference in its entirety.

FIELD

This disclosure relates to powered surgical stapling instruments having a rotating drive assembly. More specifically, this disclosure relates to an adapter for connecting a staple loading unit to a powered handle assembly.

BACKGROUND

Surgical stapling devices having powered handle are known. Such devices typically include a replaceable loading unit that is releasably secured to a powered handle. An adapter assembly is used to connect the loading unit to the powered handle. The adapter assembly may be releasable from the powered handle, and thereby permit replacement, or may be integrally formed with the powered handle.

One or more drive assemblies extend from the powered handle and operably connect with the loading unit when the loading unit is secured to the adapter assembly. In some stapling devices, the drive assembly rotates a drive screw in the loading unit that advances a sled to cause closing of a jaw assembly of the loading unit and stapling of tissue between jaws of the jaw assembly. A high force is reached with the drive assembly at the end of the stapling stroke when the sled reaches the end of its travel, or in the event of a misfire when the sled jams or otherwise locks with the jaw assembly, which may damage the adapter assembly and/or the handle assembly.

It would be beneficial to have a mechanism that prevents damage to the adapter assembly and/or handle assembly when a high force is experienced within the drive assembly.

SUMMARY

Accordingly, an adapter for releasably connecting a loading unit to a handle assembly includes a proximal drive shaft, a distal drive shaft, and a shear pin connecting the proximal drive shaft to the distal drive shaft. The proximal drive shaft includes proximal and distal portions. The proximal portion of the proximal drive shaft is configured for releasable connection to the handle assembly. The distal drive shaft includes proximal and distal portions. The distal portion of the distal drive shaft is configured for releasable connection to the loading unit. The shear pin is configured to rotationally fix the proximal drive shaft to the distal drive shaft and is configured to fracture to permit rotation of the proximal drive shaft independent of rotation of the distal drive shaft when a predetermined torque is applied to the distal drive shaft.

In certain aspects of the disclosure, the proximal portion of the distal drive shaft includes an annular flange, and the distal portion of the proximal drive shaft is received within the annular flange. The annular flange of the distal drive shaft and the distal portion of the proximal drive shaft may each define an opening. The shear pin may be configured for receipt through the opening in the annular flange of the distal drive shaft and the opening in the distal portion of the proximal drive shaft.

In some aspects of the disclosure, the adapter includes a locking plate that releasably secures the adapter to the handle assembly and the loading unit. The adapter may also include a button member secured to the locking plate. Movement of the button member may cause corresponding movement of the locking plate. The button member may be movable from a distal position in which the adapter is secured to the handle assembly and the loading unit, to a proximal position in which the adapter is releasable from the handle assembly and the loading unit.

In other aspects of the disclosure, the adapter includes first and second housing sections that rotationally support the proximal and distal drive shafts. The adapter may include a sleeve. The first and second housing sections may be received within the sleeve. The adapter may also include a spacer positioned between the proximal drive shaft and the distal drive shaft.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the disclosure are described herein with reference to the accompanying drawings, wherein:

FIG. 1 is a perspective view of a surgical stapling instrument including a handle assembly and a loading unit that is connected to the handle assembly by an adapter according to aspects of the disclosure;

FIG. 2 is an enlarged view of the indicated area of detail shown in FIG. 1;

FIG. 3 is a perspective side view of the adapter shown in FIG. 1;

FIG. 4 is a perspective view of the adapter shown in FIG. 1, with parts separated;

FIG. 5 is an enlarged view of the indicated area of detail shown in FIG. 4;

FIG. 6 is a side, cross-sectional view of the adapter shown in FIG. 3, taken along section line 6-6 shown in FIG. 2, with a locking plate and a button member of the adapter in a locked position;

FIG. 7 is the cross-sectional view of the adapter shown in FIG. 6, with the locking plate and the button member of the adapter in an unlocked position;

FIG. 8 is a cross-sectional view of the adapter shown in FIG. 3, taken along section line 8-8 shown in FIG. 6, with a shear pin of the adapter intact;

FIG. 9 is side, cross-sectional view of an end effector of the loading unit of the surgical stapling instrument shown in FIG. 1 taken along section line 9-9, with a cartridge assembly of the end effector removed; and

FIG. 10 is the cross-sectional view of the adapter shown in FIG. 8, subsequent to shearing or fracturing of the shear pin.

DETAILED DESCRIPTION

Aspects of the disclosed adapter for surgical instruments having at least one rotating drive assembly are described in detail with reference to the drawings, in which like reference numerals designate identical or corresponding elements in each of the several views. As used herein the term “distal” refers to that portion of the adapter assembly or surgical device, or component thereof, farther from the clinician, while the term “proximal” refers to that portion of the adapter assembly or surgical device, or component thereof, closer to the clinician. As used herein the term “clinician” refers to a user, a surgeon, an assistant, or any other medical personnel involved with a surgery.

FIG. 1 illustrates a surgical stapling instrument 5 including an adapter in accordance with aspects of the disclosure, shown generally as adapter 100, releasably connecting a loading unit 50 with an adapter assembly 20 of a powered handle assembly 10.

The surgical stapling instrument 5 will only be described to the extent necessary to fully disclose the aspects of the disclosure. For a detailed description of the structure and function of exemplary powered handle assemblies, please refer to U.S. Pat. Nos. 9,055,943 and 9,023,014. For a detailed description of the structure and function of exemplary adapter assemblies and loading units, please refer to U.S. Pat. No. 10,117,650.

The powered handle assembly 10 includes a handle 12 and the adapter assembly 20. The handle 12 is configured for operable engagement by a user and includes a battery (not shown) and a motor (not shown) for rotating a drive shaft 22 (FIG. 6) extending through the adapter assembly 20. Although shown and described including only a single drive shaft, it is envisioned that the powered handle assembly 10 may include multiple drive members. The function of the drive shaft 22 as described includes effectuating clamping and stapling of tissue. However, it is envisioned that rotation of the drive shaft 22 may effectuate alternative functions, e.g., articulation of the end effector 50.

The adapter assembly 20 may be integrally formed with the powered handle assembly 10 or may be configured for releasable connection with the powered handle assembly 10. Although shown and described as used with a powered handle assembly 10, it is envisioned that the aspects of the adapter 100 may be modified for use with a manually actuated handle assembly (not shown).

As shown, the loading unit 50 includes a linear stapling end effector 52. In aspects of the disclosure, the loading unit 50 is a multiple use loading unit (“MULU”) in that it is configured to releasably receive a staple cartridge assembly, e.g., staple cartridge 64. Although aspects of the adapter 100 are shown and described with reference to the loading unit 50, it is envisioned that the adapter 100 may be modified for use with any surgical instrument that includes a drive assembly with a rotating shaft.

FIG. 2 illustrates the adapter 100 of the surgical stapling instrument 5 (FIG. 1) securing the loading unit 50 to the adapter assembly 20 of the powered handle assembly 10. As will be described in further detail below, when the adapter 100 is in a locked condition, a button member 140 of the adapter 100 is in a distal or locked position.

FIGS. 3 and 4 illustrate the adapter 100 separated from the loading unit 50 and the adapter assembly 20. The adapter 100 includes upper and lower housing sections 110, 120, a locking plate 130 slidably supported relative to the upper housing 110, the button member 140 affixed to the locking plate 130, and a drive transfer assembly 150 supported within and extending through the upper and lower housing sections 110, 120. The upper and lower housing sections 110, 120 are secured together within an outer sleeve 102, and are secured within the outer sleeve 102 by rivets or pins 104. As will be described in further detail below, a spring 138 biases the locking plate 130 to a locked position (FIG. 5).

Each of the upper and lower housing sections 110, 120 define a longitudinal channel 111, 121 that, when received within the outer sleeve 102, form a longitudinal passage 103 for receipt of the drive transfer assembly 150. The upper housing section 110 includes a first flange 112 and a second flange 114 and defines a cutout 113 between the first and second flanges 112, 114. The first and second flanges 112, 114 support the locking plate 130 and a portion of the locking plate 130 is slidable received within the cutout 113. As shown, the upper and lower housing sections 110, 120 are secured together and/or maintained in a longitudinal fixed relationship with one another by tongues 116 and grooves 117, or in any other suitable manner. It is envisioned that the upper and lower housing sections 110, 120 need not be secured to one another, and may instead be maintained relative to each other through receipt within the outer sleeve 102.

The locking plate 130 of the adapter 100 includes a planar body 132. A proximal portion 132 a of the planar body 132 includes a latch 134 for engaging a tab 24 (FIG. 6) of the adapter assembly 20 (FIG. 1) of the powered handle assembly 10. A distal portion 132 b of the planar body 132 is configured to be received within a slot 51 (FIG. 5) of the loading unit 50. The locking plate 130 releasably secures the loading unit 50 with the powered handle assembly 10.

The locking plate 130 of the adapter 100 defines a first elongate opening 133 in the proximal portion 132 a of the planar body 132, a second elongate opening 135 in the distal portion 132 b of the planar body 132, and a pair of openings 137 disposed between the first and second elongate openings 133, 135. The first and second elongate openings 133, 135 of the locking plate 130 receive the respective first and second flanges 112, 114 of the upper housing section 110 of the adapter 100. The first and second openings 133, 135 are sized to permit longitudinal movement of the locking plate 130 relative to the upper housing section 110 when the first and second flanges 112, 114 are received within the respective first and second elongate openings 133, 135.

The locking plate 130 of the adapter 100 includes a prong 136 extending into the first opening 133. The prong 136 of the locking plate 130 supports the spring 138 that biases the locking plate 130 to its locked position. (FIG. 5).

The button member 140 of the adapter 100 is configured for operable engagement by a clinician. The button member 140 may include a marking or markings identifying the purpose of the button member 140. For example, and as shown, the button member 140 includes an unlock symbol 142, indicating to a clinician that movement of the button member 140 will unlock the adapter 100.

The button member 140 of the adapter 100 includes a pair of posts 144 that are received within the pair of openings 137 of the locking plate 130. The pair of posts 144 may be secured to the locking plate 130 by friction fit, welding, riveting, adhesives, screws, or other mechanical fasteners.

The drive transfer assembly 150 of the adapter 100 includes a proximal drive shaft 160 and a distal drive shaft 170 releasably secured to the proximal drive shaft 160 by a shear pin 152. More particularly, the proximal drive shaft 160 of the drive transfer assembly 150 includes an insertion portion 162 and an annular flange 164 disposed proximal of the insertion portion 162. An opening 163 extends through the insertion portion 162. The distal drive shaft 170 of the drive transfer assembly 150 includes an annular sleeve 172 defining a recess 171 (FIG. 6) sized to receive the insertion portion 162 of the proximal drive shaft 160, and an opening 173 extending transversely through the annular sleeve 172 for receiving the shear pin 152. The opening 173 in the distal drive shaft 170 is aligned with the opening 163 in the proximal drive shaft 160 to permit receipt of the shear pin 152 within the openings 163, 173. A spacer 156 is disposed about the insertion portion 162 of the proximal drive shaft 160 and is received between the annular flange 164 of the proximal drive shaft 160 and the annular sleeve 172 of the distal drive shaft 170.

As shown, a proximal end of the proximal drive shaft 160 defines an opening 165 (FIG. 6) that receives an extension 22 a (FIG. 6) of the drive shaft 22 that extends from the powered handle assembly 10 (FIG. 1) of the surgical stapling instrument 5. A distal end of the distal drive shaft 170 includes an extension for receipt within a recess 55 (FIG. 6) of a drive shaft 54 in the loading unit 50 of the surgical stapling instrument 5. It is envisioned that the proximal drive shaft 160 of the adapter 100 may be releasably connected to the drive shaft 22 of the powered handle assembly 10 and the distal drive shaft 170 of the adapter 100 may be releasably connected to the drive shaft 54 of the loading unit 50 in any suitable manner.

FIG. 5 illustrates the shear pin 152 of the drive transfer assembly 150. The shear pin 152 includes a cylindrical body 152 a having a central body portion 154 a, and first and second end portions 154 b, 154 c. As will be described in further detail below, the first and second end portions 154 b, 154 c of the shear pin 152 are configured to shear off from the central body portion 154 a of the shear pin 152 to prevent damage to the adapter assembly 20 (FIG. 1) and/or the powered handle assembly 10 when a predetermined force is reached in the drive transfer assembly 150 (FIG. 4). More particularly, the first and second end portions 154 b, 154 c of the shear pin 152 are configured to shear from the central body portion 154 a of the shear pin 152 when the distal drive shaft 160 locks or is otherwise prevented from movement. This may occur when a drive sled 70 of the end effector 60 is completely driven through the jaw assembly, or when the end effector 60 misfires and the drive sled 70 locks up and is no longer able to advance. In either event, continued rotation of the distal drive shaft 170, which could cause serious damage to the adapter assembly 20 and/or the powered handle assembly 10 without intervention, is prevented.

In one aspect of the disclosure, the shear pin 152 defines annular grooves 155 a, 155 b between the respective first and second end portions 154 b, 154 c of the shear pin 152 and the central body portion 154 a of the shear pin 152. The annular grooves 155 a, 155 b provide weakened locations along the cylindrical body 152 a of the shear pin 152 to facilitate shearing of the first and second end portions 154 b, 154 c from the body portion 154 a. It is envisioned that the shear pin 152 may instead include through holes (not shown), scoring, or be otherwise configured to facilitate shearing of the first and second end portions 154 b, 154 c from the body portion 154 a. It is also envisioned that the shear pin 152 may include a single annular groove.

FIG. 6 illustrates the adapter 100 securing the loading unit 50 connected to the adapter assembly 20 of the powered handle assembly 10 (FIG. 1). The button member 140 is in the locked position such that the loading unit 50 cannot be separated from the adapter 100 and the adapter assembly 20 cannot be separated from the adapter 100. In the locked position, the button member 140 is in a distal most position and is maintained in the locked position by a bias of the spring 138. In the locked position, the latch 134 on the proximal portion 132 a of the locking plate 130 of the adapter 100 engages the tab 24 of the adapter assembly 20 and the distal portion 132 b of the locking plate 130 is received within the slot 51 of the loading unit 50 to prevent separation of the adapter assembly 20 and loading unit 50 from the adapter 100.

FIG. 7 illustrates the adapter 100 with the button member 140 in an unlocked position. In the unlocked position, the button member 140 is moved against the bias of the spring 138 to a proximal-most or unlocked position. In the unlocked position, the latch 134 on the proximal portion 132 a of the locking plate 130 of the adapter 100 is spaced from the tab 24 of the adapter assembly 20 and the distal portion 132 b of the locking plate 130 is withdrawn from the slot 51 in the loading unit 50. When the button member 140 is in unlocked position, the loading unit 50 may be separated from the adapter 100 and the adapter 100 may be separated from the adapter assembly 20 and/or the powered handle assembly 10.

FIG. 8 illustrates a cross-sectional view of the drive transfer assembly 150 taken through the shear pin 152 connecting the proximal and distal drive shafts 160, 170 together. During normal operation of the surgical stapling instrument 5 (FIG. 1), rotation of the proximal drive shaft 160 causes rotation of the distal drive shaft 170.

FIG. 9 illustrates the end effector 60 of the loading unit 50. The end effector 60 includes an anvil assembly 62 and a cartridge assembly 64. A drive screw 66 extends through and is rotationally supported by the cartridge assembly 64 (FIG. 1). The drive screw 66 is operably connected to the distal drive shaft 170 (FIG. 8) such that rotation of the distal drive shaft 170 causes rotation of the drive screw 66. A clamping member 68 operably engages the drive screw 66 and is configured to longitudinally move along the drive screw 66 upon rotation of the drive screw 66. The end effector 60 further includes a sled 70 that is engaged by the clamping member 68 as the clamping member 68 is advanced through the cartridge assembly 64 to cause the ejection of staples (not shown) from a staple cartridge 64 a (FIG. 1) of the cartridge assembly 64.

FIG. 10 illustrates a cross-sectional view of the drive transfer assembly 150 taken through the shear pin 152 connecting the proximal and distal drive shafts 160, 170 to each other subsequent to shearing of the shear pin 152. As described above, when the sled 70 of the end effector 60 of the loading unit 50 is prevented from further advancement, e.g., reaches the terminus of the drive stroke, or binds with the cartridge assembly 64 (FIG. 1), the drive screw 66 is prevented from turning. Forcing the drive screw 66 to turn when it cannot be further turned may cause damage to the adapter assembly 20 (FIG. 1) and/or the powered handle assembly 10. To prevent damage to the adapter assembly 20 and/or the powered handle assembly 10, the first and second end portions 154 b, 154 c of the shear pin 152 are sheared or fracture from the central body portion 154 a of the shear pin 152 to permit continued rotation of the proximal drive shaft 160 independent of the distal drive shaft 170.

Subsequent to shearing of the shear pin 152, the adapter 100 of the surgical stapling instrument 5 (FIG. 1) no longer operates to actuate the end effector 60 of the loading unit 50. More particularly, shearing of the shear pin 152 separates the connection between the proximal and distal drive shafts 160, 170 that is not repairable without replacing the shear pin 152. Prior to reusing the surgical stapling instrument 5 (FIG. 1) the adapter 100 is replaced with a new adapter 100. In this manner, it is envisioned that a new adapter 100 may be used with every new firing of the surgical stapling instrument 5.

Any of the components described herein may be fabricated from either metals, plastics, resins, composites or the like taking into consideration strength, durability, wearability, weight, resistance to corrosion, ease of manufacturing, cost of manufacturing, and the like.

It will be understood that various modifications may be made to the aspects of the disclosed adapters. Therefore, the above description should not be construed as limiting, but merely as exemplifications of aspects of the disclosure. Those skilled in the art will envision other modifications within the scope and spirit of the disclosure. 

What is claimed is:
 1. An adapter for releasably connecting a loading unit to a handle assembly, the adapter comprising: a proximal drive shaft having a proximal portion and a distal portion, the proximal portion of the proximal drive shaft being configured for releasable connection to the handle assembly; a distal drive shaft having a proximal portion and a distal portion, the distal portion of the distal drive shaft being configured for releasable connection to the loading unit; and a shear pin connecting the proximal drive shaft to the distal drive shaft, wherein the shear pin is configured to rotationally fix the proximal drive shaft to the distal drive shaft and is configured to fracture to permit rotation of the proximal drive shaft independent of rotation of the distal drive shaft when a predetermined torque is applied to the distal drive shaft.
 2. The adapter of claim 1, wherein the proximal portion of the distal drive shaft includes an annular flange, and the distal portion of the proximal drive shaft is received within the annular flange.
 3. The adapter of claim 1, wherein the annular flange of the distal drive shaft and the distal portion of the proximal drive shaft each define an opening.
 4. The adapter of claim 3, wherein the shear pin is configured to be received through the opening in the annular flange of the distal drive shaft and the opening in the distal portion of the proximal drive shaft.
 5. The adapter of claim 1, further including a locking plate that releasably secures the adapter to the handle assembly and the loading unit.
 6. The adapter of claim 5, further including a button member secured to the locking plate, wherein movement of the button member causes corresponding movement of the locking plate.
 7. The adapter of claim 6, wherein the button member is movable from a distal position in which the adapter is secured to the handle assembly and the loading unit, to a proximal position in which the adapter is releasable from the handle assembly and the loading unit.
 8. The adapter of claim 1, further including a first housing section and a second housing section that rotationally support the proximal and distal drive shafts.
 9. The adapter of claim 8, further including a sleeve, wherein the first and second housing sections are received within the sleeve.
 10. The adapter of claim 1, further including a spacer positioned between the proximal and distal drive shafts.
 11. A surgical stapling instrument comprising: a handle assembly; and an adapter releasably connectable to the handle assembly, the adapter including, a proximal drive shaft having a proximal portion and a distal portion, the proximal portion of the proximal drive shaft being configured for releasable connection to the handle assembly; a distal drive shaft having a proximal portion and a distal portion, the distal portion of the distal drive shaft being configured for releasable connection to the loading unit; and a shear pin connecting the proximal drive shaft to the distal drive shaft, wherein the shear pin is configured to rotationally fix the proximal drive shaft to the distal drive shaft and is configured to fracture to permit rotation of the proximal drive shaft independent of rotation of the distal drive shaft when a predetermined torque is applied to the distal drive shaft.
 12. The surgical stapling instrument of claim 11, wherein the proximal portion of the distal drive shaft includes an annular flange, and the distal portion of the proximal drive shaft is received within the annular flange.
 13. The surgical stapling instrument of claim 11, wherein the annular flange of the distal drive shaft and the distal portion of the proximal drive shaft each define an opening.
 14. The surgical stapling instrument of claim 13, wherein the shear pin is configured to be received through the opening in the annular flange of the distal drive shaft and the opening in the distal portion of the proximal drive shaft.
 15. The surgical stapling instrument of claim 11, further including a locking plate that releasably secures the adapter to the handle assembly and the loading unit.
 16. The surgical stapling instrument of claim 15, further including a button member secured to the locking plate, wherein movement of the button member causes corresponding movement of the locking plate.
 17. The surgical stapling instrument of claim 16, wherein the button member is movable from a distal position in which the adapter is secured to the handle assembly and the loading unit to a proximal position in which the adapter is releasable from the handle assembly and the loading unit.
 18. The surgical stapling instrument of claim 11, further including a first housing section and a second housing section that rotationally support the proximal and distal drive shafts.
 19. The surgical stapling instrument of claim 18, further including a sleeve, wherein the first and second housing sections are received within the sleeve.
 20. A surgical stapling instrument comprising: a handle assembly; a loading unit; and an adapter releasably connecting the loading unit to the handle assembly, the adapter including, a proximal drive shaft having a proximal portion and a distal portion, the proximal portion of the proximal drive shaft being configured for releasable connection to the handle assembly; a distal drive shaft having a proximal portion and a distal portion, the distal portion of the distal drive shaft being configured for releasable connection to the loading unit; and a shear pin connecting the proximal drive shaft to the distal drive shaft, wherein the shear pin is configured to rotationally fix the proximal drive shaft to the distal drive shaft and is configured to fracture to permit rotation of the proximal drive shaft independent of rotation of the distal drive shaft when a predetermined torque is applied to the distal drive shaft. 